Having lost a manual awning on our TT due to a sudden downpour (I was taking a nap), you can put all the tie downs and angles you like, but if it fills faster than it drains, look out. And after it ages a bit, you just can't get it taunt enough to really protect it, even with tie downs and anti-flappers.
One thing I really like about the electric awning on the 3670 is it's too high for the wife to hang her bazillion little lights from. And I won't be leaving it extended, unattended.